无创产前检测在高龄孕妇中的临床应用

The clinical application of NIPT in pregnant women of advanced maternal age

目的探讨无创产前检测在高龄孕妇胎儿染色体非整倍体检出中的临床应用。方法选取2017年12月至2018年12月期间在中国人民解放军北部战区总医院产前诊断中心就诊的高龄孕妇1 425例为研究组,行无创产前检测胎儿染色体非整倍体,结果高风险者自愿行羊膜腔穿刺术,进行羊水细胞染色体核型分析,计算阳性预测值。选取266例高龄孕妇为对照组,直接进行羊水细胞染色体核型分析。比较两组胎儿染色体非整倍体检出情况。结果研究组中检出胎儿染色体非整倍体高风险34例(25例21-三体,5例18-三体,2例13-三体,2例性染色体数目异常),行羊水细胞染色体核型分析后确定染色体非整倍体29例(23例21-三体,4例18-三体,1例13-三体,1例45, XO),总体阳性预测值为85.29%(21-三体为92.00%,18-三体为80.00%,13-三体为50.00%,性染色体数目异常为50.00%)。对照组中检出胎儿染色体非整倍体6例(5例21-三体,1例18-三体)。两组检出率比较差异无统计学意义(χ^2=0.02,P>0.05)。结论无创产前检测高龄孕妇胎儿染色体非整倍体阳性预测值高,特别适用于有介入性产前诊断禁忌的高龄孕妇,可有效避免侵入性诊断的风险,降低对孕妇和胎儿的伤害。

Objective To explore the clinical value of Non-invasive Prenatal Testing(NIPT) in pregnant women of advanced maternal age. Methods For the research Group, 1,425 pregnant women of advanced maternal age were admitted to the hospital during the period from December, 2017 to December 2018, and they underwent NIPT. Then, those with a higher risk volunteered to receive amniocentesis to analyze the karyotyping of amniotic fluid cells and calculate the positive predictive value. For the Control Group, 266 pregnant women of advanced maternal age underwent amniocentesis voluntarily to analyze the karyotypes of amniotic fluid cells. The results of the two groups were compared and analyzed. Results In the Research Group, 34 cases were found to be the high-risk ones of fetal chromosomal aneuploidy(25 cases with trisomy 21, 5 cases with trisomy 18, 2 cases with trisomy13, 2 cases with sex chromosome aneuploidy). Further analysis of the karyotype of amniotic fluid cells identified 29 cases of chromosome aneuploidy(23 cases with T21, 4 cases with T18, 1 case with T13, 1 case with 45, XO), and the positive predictive value was 85.29%(T21-92.00%, T18-80.00%, T13-50.00%, sex chromosome aneuploidy were 50.00%). In the Control Group, 6 cases with chromosome aneuploidy were identified(5 cases with T21;1 case with T18). There was no significant difference between the two groups(χ^2 = 0.02, P>0.05). Conclusion NIPT has a high detection rate of fetal chromosomal aneuploidy, which can be recommended for pregnant women of advanced maternal age, especially for the women with contraindication for interventional diagnosis, and it can effectively prevent the risk of invasive diagnosis, thus further reducing the incidence of birth defects。